1. Technical Field
The present invention relates to a laser light source apparatus having a wavelength conversion element.
2. Related Art
To enhance the brightness of an image display apparatus, such as a projector, a laser light source is used as the light source apparatus in some cases. Such a laser light source uses a more efficient, longer-wavelength laser light source and a wavelength conversion element to provide visible laser light.
JP-T-2004-503923 is an example of related art (the term “JP-T” as used herein means a published Japanese translation of a PCT patent application).
The visible laser light provided by such wavelength conversion, however, also has higher coherence than that of a discharge lamp light source and the like. Laser light interference therefore occurs, so that speckle noise appears on the image projection screen of the image display apparatus. Such speckle noise could disadvantageously reduce image quality of the projected image. Such a problem may occur not only in the light source apparatus used in an image display apparatus but also in various apparatuses that require light source apparatuses, such as illumination apparatuses